3 replies to this topic

[Nina1119]

Hello,

Are there any general guidelines or sheets that can be used to design a HCl scrubber which uses caustic(20%) as the scrubbing liquid? Are heat calculations necessary for this type of scrubber? Is there a typical pressure drop, gas factor, liquid load, height and diameter for such scrubbers?

Please help.

Thank you.

[breizh]

Hi ,

Consider this resource :
http://www.jaeger.co...asscrubbing.pdf

Breizh

[siretb]

HCl scrubbing is easy. Just be sure you have no aerosols before.the scrubber
Unless HCl is very concentrated in the gas, you may neglect the enthalpy of reaction. Some water is generally evaporated in the process, and, very often you end up ,at the so called "adiabatic temperature'n, often between 45°C and 65°C.
Using a packed tower (not the only option) count 2 transfer units per meter of packing, and a wetting rate of at least 20 m3/m2/hour.
Caustic consumption is on a 1:1 molar basis
The gas velocity would be around 2-3 m/s (packing dependant)
For each case, pressure drop will need calculation based on the actual flows (L and V, packing type, ).
If scrubber diameter is very small (less than 500mm diameter) than a smaller packing will be selected, with a higher efficiency, but also a higher pressure drop.
Note that one can scrub HCl without caustic, too.

[djack77494]

siretb,
Nice concise and useful summary of the factors that enter into the design. There are plenty of theoretical papers on the various challenges we face all the time. It's refreshing to hear a practical approach every now and then.